1. Field of the Invention
This invention relates to a method and an apparatus for forming identification data for demonstrating authenticity of the user of a peripheral device in making data communications with other peripheral devices or computer centers in the data communication network including a plurality of peripheral devices for data communication and computer centers.
2. Description of the Prior Art
In a data communication network including a plurality of peripheral device for data communication and a computer center or centers in general, it is necessary to check that the user is authorized to use the network and to cipher the data transmitted through the communication network, in order to enable only the authorized user to have access to the host machine to assure data security such as data confidentiality.
Heretofore, in checking that the user is an authorized user, identification data allocated to each user and the password optionally designated by the user are registered at a host machine. The user transmits the identification data and the password from the terminal machine to the host machine and the identification data and the password received at the host machine are compared with the identification data and the password registered at the host machine.
For example, in a cash dispenser making use of an on-line system of banking facilities, an ID card such as a magnetic card or an IC card with prerecorded identification data of a user is utilized to demonstrate that the user is an authorized user of a bank account. The method of identifying a person by an IC card is shown for example in the Japanese Laid-open Patent Publication No. 146361/1985.
On the other hand, data transmitted through a communication network are protected by ciphering the data on the communication network by a ciphering device of the DES or RSA system provided on the communication network.
It is noted that, in the data communication network in general, the password optionally designated by the user is apt to be decoded and, once the ID card is forged or stolen, it becomes impossible to identify the authorized user, so that the chance that the host machine is illegally accessed is increased. On the other hand, the identification data allocated to the user are formed by a dedicated data processing device at the time of the preparation of the ID card or at a host machine of the data communication network. There is the risk of theft of the data processing device, the identification data formation algorithm at the host machine or of the identification data per se. Thus a demand has been raised for evolving the method and the apparatus for forming the identification data of high data security or confidentiality.